1. Field of the Invention
The invention relates to slide fastener stringers and to their method and apparatus of manufacture wherein each stringer has head portions of a continuous filament coupling element extending from slots in a folded edge of a support member.
2. Description of the Prior Art
The prior art, as exemplied in U.S. Pat. No. 1,557,303, No. 1,933,390, No. 1,937,297, and No. 3,430,304 and British Patent Specification No. 1,161,016, contains a number of slide fasteners having continuous chains of coupling elements or the like secured within a fold of a carrier tape wherein the head portions of the coupling elements extend from slots across the folded edge of a leather or fabric strip or extend from apertures formed by weft threads and a wide spacing between warp threads of woven carrier tape. The prior art slots and apertures extend perpendicular to the folded edge of the carrier tape; such perpendicular slots in slide fasteners employing spiral or coil type fastening elements result in excessive distortion and relatively inferior support for the spiral coupling elements.